The foot and ankle are often overlooked in exercise programs, yet feet and ankles are extremely important areas of the body. Unfortunately, injuries to the foot or ankle are common in a variety of sports, work activities, or activities of daily living. Many treatment methods are available to deal with foot and ankle injuries (chiropractic adjustments, inflammation-reduction treatments such as ultrasound or microcurrent, range of motion exercises, coordination and balance exercises such as wobble board, strengthening exercises using resistive strength equipment, orthotics, etc.). However, none of the treatments or devices commonly utilized in the health care and exercise fields offers a complete range of exercises to properly strengthen the foot and ankle in isolation or in a combination of movements (e.g. functional movements). Also, existing foot exercising devices do not easily allow a patient to perform passive (i.e. with muscles relaxed) range of motion exercises. Passive exercises can be beneficial during early-stage rehabilitation. Furthermore, existing devices do not easily allow for eccentric loading of the musculature of the foot and ankle in a non-weight-bearing manner. Eccentric loading has been shown to be very effective in rehabilitating chronic tendonitis. Eccentric loading involves allowing a muscle to elongate while the muscle is under tension.
Balanced strengthening of the foot and ankle requires resistance exercises in multiple directions. Performing calf raises using body weight as resistance or with strength training equipment will strengthen the foot and ankle in plantar flexion; however, this results in unidirectional strengthening only. Various health practitioners recommend that patients grasp towels with their toes to strengthen the plantar musculature of the foot. Although this provides some resistance, it is cumbersome and there is limited opportunity to increase or monitor the resistance. Progressive increases in resistance are important to allow for strengthening of the associated musculature. Although conventional elastic tubing apparatus can provide resistance to strengthen the foot in simple directions such as dorsiflexion, it is difficult to properly orient the tubing to strengthen the foot and ankle in multiple directions. Furthermore, it is sometimes difficult to apply the tubing to the foot so that the resistance is applied in the appropriate direction (e.g. sub-talar inversion/eversion).
Currently prevalent foot and ankle strengthening techniques can help to strengthen the foot somewhat; however, these techniques are typically limited by one or more of:                inadequate activation of the intrinsic musculature that controls movement of the foot and toes,        difficulty in set-up of the apparatus and anatomical landmarking,        lack of progressive resistance,        lack of a way to measure resistance,        unidirectional strengthening; and        inability to provide eccentric loading.        
Foot and ankle exercising devices that are described in the patent literature include:                Johnson et al., U.S. Pat. No. 6,821,235 which discloses a foot-engaging element that can move in a spherical pattern and has elastic straps that provide resistance to movement.        Kucharik et al. U.S. Pat. No. 4,739,986 discloses a foot ankle and lower leg exerciser that has two foot pedals mounted on a bar. A lower end of the bar has a ball joint that allows the foot pedals to be moved. A spring provides resistance to movement.        Firster, U.S. Pat. No. 3,984,100 discloses a foot exerciser having a foot support to which can be attached weights or the like. A rounded member under the foot support allows the foot support to be pivoted relative to the floor.        Kost, U.S. Pat. No. 2,206,902 discloses a device having foot platforms pivotally mounted to a base.        Mason et al., U.S. Pat. No. 5,186,698 discloses an ankle exercise system comprising an elastic strap that can be attached to a user's forefoot.        Aberton et al., U.S. Pat. No. 6,540,651 discloses exercise apparatus having a sock-like attachment structure. The attachment structure can be worn on a foot and has several different places to which one end of a resistance member can be attached. Another end of the resistance member can be attached to a structure;        Williams, U.S. Pat. No. 4,371,161 discloses a foot exerciser having an elastic member extending between a foot-encircling strap and a brace attached to a user's lower leg;        Fulton, U.S. Pat. No. 4,728,103 discloses a leg and ankle exercising device comprising a plate attached to handles by elastic limbs;        Dyer, U.S. Pat. No. 6,110,078 discloses a device for stretching the foot. The device has two plates hinged together and a variable tensioning mechanism connected between the plates;        Drago, U.S. Pat. No. 5,413,543 discloses a device for exercising the toes, foot and ankle. The device has a lower stationary platform that is attached to an upper movable platform by a platform spring. A toe gripping bar is mounted on a spring mechanism.        Molloy, U.S. Pat. No. 4,478,414 discloses a device having a noose that wraps around a user's foot. The noose is attached to a securing strap by elastic members. The securing strap can be attached to the back of a chair.        Collier, U.S. Pat. No. 5,039,093 discloses a device that has a ring-like structure that attaches around the upper leg. An elongated finger-like structure is attached to each of the user's toes by an elastic element.        Chism et al, U.S. Pat. No. 5,582,579 discloses an orthopedic device which includes a boot that receives the user's foot and ankle. Manipulation straps attach to either side of the boot. A user can move the knee and ankle joints through flexion movements while applying tension on the manipulation straps.        A selection of other devices for exercising the foot and/or lower leg are disclosed in: Stodgell, U.S. Pat. No. 5,368,536; McLeod, U.S. Pat. No. 5,897,464; McIlvain et al. U.S. Pat. No. 5,749,668; Commisso, U.S. Pat. No. 6,878,102; Timmer, U.S. Pat. No. 6,811,523; Knight, U.S. Pat. No. 6,390,957; Hayes, U.S. Pat. No. 6,312,361; Lundberg, U.S. Pat. No. 6,109,990; Vathappallil, U.S. Pat. No. 6,063,013; Howd et al. U.S. Pat. No. 6,063,010; Thompson, U.S. Pat. No. 5,860,423; Foster, U.S. Pat. No. 5,645,516; Perez, U.S. Pat. No. 5,618,247; Jennings, U.S. Pat. No. 5,836,587; Johnston, U.S. Pat. No. 5,277,680; Bastow, U.S. Pat. No. 5,215,508; McIntyre, U.S. Pat. No. 5,178,596; Porter et al., U.S. Pat. No. 5,100,129; Powers, U.S. Pat. No. 5,004,228; Scott, U.S. Pat. No. 4,998,722; Kock, U.S. Pat. No. 4,979,737; Ostergard, U.S. Pat. No. 4,767,118; McIntyre, U.S. Pat. No. 4,650,183; Troxel, U.S. Pat. No. 4,605,220; Bangerter et al., U.S. Pat. No. 4,600,188; Martinez, U.S. Pat. No. 4,461,472; Lepley et al., U.S. Pat. No. 4,452,447; Hoyle et al., U.S. Pat. No. 4,337,939; White, U.S. Pat. No. 4,310,155; Leseberg, U.S. Pat. No. 4,251,070; Fiore et al., U.S. Pat. No. 4,186,920; Freeman Jr., U.S. Pat. No. 3,421,760; Matt Sr., U.S. Pat. No. 3,295,847; Loomis et al. U.S. Pat. No. 4,306,714; Scott, U.S. Pat. No. 4,998,722; Cunningham, U.S. Pat. No. 2,160,722; Marshman, U.S. Pat. No. 2,097,376; Gailey, U.S. Pat. No. 1,952,750; Anderson, U.S. Pat. No. 1,671,096; Kheiralla, U.S. Pat. No. 539,872; Gilchrist, US 2007/0287615; Nitta et al, US 2005/0043150; Backes et al. US 2005/0209067; and Knight, US 2002/0137608 A1.        
There is a need for effective, practical apparatus and methods for strengthening muscles of the foot and lower leg.